Bamboo builds are not triggered through bitbucket server

I have an application link between Bitbucket server and Bamboo Server. This works nice. Bitbucket shows information from Bamboo and vice versa. Bamboo also detects new branches in Bitbucket server. The problem, however, is that pushes to Bitbucket are not triggering bamboo builds. I looked in the logs but everything looks fine. The server URLs are: